(Jax, Keita)

Today Keita and I marked out the rough position of the back corners of ISCTEY at BSC10 to facilitate its move to its final location next to the BSC. The nominal position of the table is 18" away from the ALS viewport in the -X direction, with the left edge of the table 22" in the +Y direction from the ALS viewport (lower left viewport on BSC10). The numbers are given in inches because none of the measuring tapes we found had metric markings. Here is the information and calculations used to determine this position. 

The beam angles from the TMS were taken from sheet 7 of D0902163. Since this is the layout for EX, we need to consider the mirror image of this layout. Therefore, the horizontal angle is not in the -X direction, but in the -Y direction. The horizontal angle phi is determined from the alignment angles as outlined in the attached pdf. 

For the ALS beam angle of 12.4 degrees, the horizontal shift per meter is 22cm. The table is placed approximately half a meter from the viewport, corresponding to a shift of 11 cm/~4.25". The center of the table opening for the ALS beam is 27.5" from the edge of the table enclosure, so add this displacement to 27.5" to determine the shift in position. This gives our layout position of 22" in the +Y direction from the ALS viewport.

The only question we have remaining is the position of the table in the X direction. We have laid out and calculated a position consistent with the table installed at EX, but there is some possibility the mode-matching on the table was set with a distance of 1 m in mind. If the table has to come back half a meter, this would add 11 cm to the horizontal displacement. The clearance on either side of the ALS table after moving the E-module will be 9" (ref. Bubba), so if the position has to be modified to address this, the additional 11 cm/4.25" will be attainable with our available space. Alternatively, the mode-matching telescope on the table can be adjusted to be optimal for this position, which is more consistent with the table as installed at EX. 

(Edited because the equations were exported as PDFs instead of PNGs and didn't show up... and AGAIN because despite showing up just fine in the previews, the equations refuse to show up. Attached the work as a pdf.)